The invention described herein relates generally to a system and method for remotely managing a production environment. Specifically, the invention aggregates digital data sources originating from computer controlled production machinery into a single bidirectional data link to a centralized remote site where data can be stored and analyzed and from which control, modification and maintenance of the production machinery can be effected.
In a typical production environment, a diverse assortment of automated machinery is used to produce finished products from raw materials. Although older machines may still have analog or mechanical systems to regulate their operation, newer production machines are generally digitally controlled and use microprocessors to keep them operating within desired parameters. In general, each digitally controlled machine is provided with its own microprocessor in a “control unit” that is connected to a plurality of sensors and/or actuators strategically located on the machine. These sensors and actuators are well known in the art and are specifically tailored to monitor and control one or more operating parameters such as temperature, pressure, humidity, viscosity, spindle speed, etc. that are critical to a specific machine.
The control unit of a production machine generally has a terminal or control panel to allow human machine operators and engineers to interface with the control unit, and thus to monitor and control the operation of the production machine. In cases where the control unit provides information to a human operator in real time, the operator can react to changes in production or machine status based on information provided by the control unit. For example, in response to an alarm received from a control unit due to an overheated bearing, an operator may adjust the operating speed of the equipment to prevent damage to the bearing. In cases where machine speed is also regulated by the control unit, the human operator can monitor bearing temperature and control the machine speed from a single terminal connected to the control unit. In some cases, configurable software running on the control units microprocessor may enable the control unit to make routine adjustments to a particular production unit automatically without the intervention of a human operator. When it is necessary, configuration of the software on the control unit's microprocessor is again typically accomplished from a control panel on the control unit itself, or from a terminal connected to the control unit.
Therefore, it can be seen that the control units typically provided on production equipment enable operational communication that is both bidirectional and takes place on two hierarchical levels. At a first hierarchical level, a human operator receives machine status information and transmits commands to the machine via the machine's control unit. This is operational communication, and commonly takes place during the ordinary course of production. However, in the event that modification or configuration of the software of the control unit is required, an engineer interfaces directly with the control unit to read and/or modify the software that dictates the manner in which the control unit carries out its function. This is configurational communication, which may be said to belong to a second hierarchical level associated with modifying the production environment itself. Having the ability to monitor an entire production environment in real-time and to undertake both operational and configurational communication of all of the machines in a production environment is necessary to the comprehensive management, or process engineering, of the production environment.
It is common in production environments for machines of different types to be used during each step of production. Although each type of machine that has a digital interface functions generally as described above, the control unit on each machine is specialized to provide diagnostic information and permit control of parameters that are relevant to that machine's specific function. Therefore, the data acquired by one control unit is likely to be different in content both operationally and configurationally from that acquired by another. Furthermore, because machines of various ages, origins and levels of sophistication may be used in a single production environment, the Input/Output (I/O) protocol used by each machine's control unit is likely to be proprietary, or otherwise incompatible with the control units of other machines. Finally, the operating system and software of the control units may differ from each other. Thus, the diversity of machinery in a typical production environment often results in a corresponding diversity of data formats, programming languages and communications protocols creating a production data topology in which each machine is isolated and depends upon the intervention of a human operator to coordinate its operation with the other machines in the production environment. This complicates the aggregation of data, and makes analysis thereof in real-time difficult.
It is known to monitor the fundamental elements of a manufacturing process through the use of sensors to measure critical aspects in the transformation of a raw material into a finished product. U.S. Pat. No. 5,668,741 to Prigent entitled “Process and Device to Continuously and in Real Time Control a Complex Manufacturing Process” discloses the monitoring of a manufacturing process wherein a plurality of sensors are deployed along a production line and connected to a computer over a network. Each sensor is provided with its own network interface circuit to convert analog sensor data into a digital signal compatible with the network. Sensor data routed to the computer may be stored on a database or analyzed in real time.
Such a system, however, is designed strictly for monitoring a process, not for the comprehensive process engineering discussed above. Therefore, in the event that analysis of the sensor output by Prigent reveals a problem, corrective modifications to the production environment must be undertaken manually or through a separate system. Furthermore, because this system requires the installation of sensors that are at once compatible with the machinery they are connected to and also compatible with the other sensors on the network, it can be difficult or expensive to install in an existing production environment. A further drawback, is that installing such specialized sensors on modern equipment may actually be redundant to the sensing and feedback systems already in place on digitally controlled production equipment.
Additionally, the control units on production equipment tend to be located in close physical proximity to the controlled machines, and thus require human operators on the production floor to perform the tasks associated with process engineering. Systems have been designed to permit the control units to be monitored remotely, such as from a single remote control center. For example, U.S. Pat. No. 4,996,655 to Chadwick et al. entitled “Real Time Monitoring of Remote Signals in an Industrial Environment” discloses a device that allows for a unidirectional connection over a data line between a control unit associated with a piece of production equipment, and a computer displaying data from the control unit located up to 500 meters away. Such a system must be specially configured to each control unit, does not aggregate the data of more than one control unit, and does not permit bi-directional communication. Therefore, real-time monitoring of more than one device is not possible without running additional data lines, making a large-scale deployment unwieldy and inflexible, especially in the event that production facilities are spread out over several remote locations. Moreover, because communication is only one-way, the system cannot pass instructions back to the control unit and thus will not allow control of the machine, or modification of the control unit's parameters from the remote location.
Therefore, a need exists for a system to enable process engineering from a centralized location remote from the production site by allowing for the migration of manufacturing data from a plurality of existing control units connected to production machinery.
A further need exists for a system allowing communication with a diverse plurality of control units associated with production machinery in a production environment over a single bidirectional data stream utilizing a standard network communications protocol without the need for the installation of specialized or redundant sensors.
A still further need exists for a system to permit control of the operating parameters of the machines in a production environment from a centralized location. Additionally, such a system should allow for reconfiguration of the microprocessor-based control units from the remote location, thereby permitting virtual process engineering of the production environment.
A still further need exists for a system that is capable of storing and analyzing data aggregated from a plurality of production equipment control units and from multiple production facilities in a centralized location to provide real-time notification of changes in the production line, predictions of likely component failures and root cause analysis of production line failures.